<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>登录</title>
</head>
<body>
<h1>欢迎访问管理后台</h1>
<form action="" method="post">
    用户名：<input type="text" name="username"><br>
    密 码：<input type="text" name="password"><br>
    <button type="submit">登录</button>
    <span style="color: red">{{ msg }}</span>
</form>
</body>
</html>